This is precisely why "situation awareness" is so important! Even if the guy had a gun, he would have been helpless. The camera showed the two attackers sitting in a car... he should have seen them as well.

Maybe situational awareness would have kept him from being surprised, when I go to the city (which is vary rarely) I know when someone is around me. I'm always aware of my surroundings anyways but it is heightened when I go there. I guess you could say I look around a lot a scan everywhere.